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1.
Psychol Sport Exerc ; 582022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34776790

RESUMEN

Research has found that greater lifetime stressor exposure increases the risk for mental and physical health problems. Despite this, few studies have examined how stressors occurring over the entire lifespan affect sport performers' health, well-being, and performance, partly due to the difficulty of assessing lifetime stressor exposure. To address this issue, we developed a sport-specific stress assessment module (Sport SAM) for the Stress and Adversity Inventory (STRAIN) and then analyzed the instrument's usability, acceptability, validity, and test-retest reliability. Furthermore, we examined whether trait-like tendencies to appraise stressful situations as a challenge or threat mediated the association between lifetime stressor exposure and health, well-being, and performance. Participants were 395 sport performers (Mage = 22.50 years, SD = 5.33) who completed an online survey. Results revealed that the Sport SAM demonstrated good usability and acceptability, good concurrent validity in relation to the Adult STRAIN (rs = 0.23 to 0.29), and very good test-retest reliability (r icc = 0.87 to 0.89). Furthermore, the Sport SAM was significantly associated with symptoms of depression (ß = 0.21 to 0.24, ps ≤ .001) and anxiety (ß = 0.13 to 0.19, ps ≤ .012), and general physical (ß = 0.24 to 0.27, ps = ≤ 0.001) and mental (ß = 0.23 to 0.32, p ≤ .001) health complaints. Finally, we found that associations between total lifetime non-sport and sport-specific stressor severity and health were mediated by trait stress appraisals. Consequently, these findings may help practitioners better identify sport performers who are at risk of developing stress-related health problems.

2.
J Sport Exerc Psychol ; 44(3): 206-219, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35468589

RESUMEN

This study examined the effect of slow diaphragmatic breathing on psychophysiological stress responses and pressurized performance. Sixty-seven participants (40 female; Mage = 20.17 ± 2.77 years) were randomly assigned to either a diaphragmatic-breathing, paced-breathing, or control group. Participants completed a nonpressurized shooting task and then received instructions about a pressurized version. Next, the diaphragmatic group was told to breathe at 6 breaths/min, the paced group at 12 breaths/min, and the control group received no instructions. Following a 5-min intervention period, participants completed the pressurized task while performance was assessed. Psychophysiological stress responses (e.g., cognitive anxiety, heart rate) were recorded throughout. Results revealed that diaphragmatic breathing had mixed effects on stress responses, with some unaffected (e.g., heart rate) and others reduced (e.g., cognitive anxiety), and little effect on performance. Findings suggested that slow diaphragmatic breathing might not aid pressurized performance but could benefit psychological stress responses.


Asunto(s)
Estrés Psicológico , Femenino , Frecuencia Cardíaca/fisiología , Humanos
3.
J Sport Exerc Psychol ; 44(6): 427-438, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36450294

RESUMEN

This study addressed whether lifetime stressor exposure was associated with psychophysiological reactivity and habituation to a novel laboratory-based stressor. Eighty-six participants (Mage = 23.31 years, SD = 4.94) reported their exposure to lifetime non-sport and sport-specific stressors before completing two consecutive trials of the Trier Social Stress Test, while cardiovascular (i.e., heart rate) and endocrine (i.e., salivary cortisol) data were recorded. Exposure to a moderate number of lifetime non-sport and sport-specific stressors was associated with adaptive cardiovascular reactivity, whereas very low or very high stressor exposure was related to maladaptive reactivity. Moreover, experiencing a very low number of lifetime non-sport (but not sport-specific) stressors was associated with poorer habituation. In contrast, lifetime stressor severity was unrelated to cardiovascular reactivity. Finally, greater lifetime non-sport and sport-specific stressor counts were associated with blunted cortisol reactivity and poorer habituation. These results suggest that lifetime stressor exposure may influence sport performers' acute stress responses.


Asunto(s)
Habituación Psicofisiológica , Deportes , Humanos , Hidrocortisona , Frecuencia Cardíaca
4.
Psychol Sport Exerc ; 522021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33281503

RESUMEN

Research suggests that elite athletes are at increased risk of poor mental health, partly due to the intense demands associated with top-level sport. Despite growing interest in the topic, the factors that influence the mental health and well-being of elite athletes remain unclear. From a theoretical perspective, the accumulation of stress and adversity experienced over the life course may be an important factor. To investigate this possibility, we employed a mixed-method design to: (a) examine whether cumulative lifetime stress predicted depression, anxiety, and well-being in elite athletes; and (b) help explain why cumulative lifetime stress exposure might have resulted in poor mental health and well-being. Ninety-five elite athletes (M age = 29.81, SD = 10.88) completed the Stress and Adversity Inventory, Patient Health Questionnaire, Generalized Anxiety Disorder 7-item scale, and the Scales of General Well-Being. Hierarchical regression analyses revealed that total count and severity of lifetime stressor exposure significantly predicted greater depression (ß = .42, p < .001; ß = .46, p < .001) and anxiety symptoms (ß = .34, p = .003; ß = .28, p = .018), and worse well-being (ß = -.42, p < .001; ß = -.30, p = .015). Semi-structured interviews were then conducted with six athletes. Thematic analysis revealed that cumulative lifetime stress exposure fostered poor mental health and well-being by promoting maladaptive long-term coping strategies, increasing susceptibility to future stress, and limiting interpersonal relationships. We believe these findings can help practitioners identify, and intervene accordingly with, elite athletes at risk of experiencing stress-related mental health problems.

5.
J Strength Cond Res ; 35(11): 3164-3169, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31268987

RESUMEN

ABSTRACT: Sant'Anna, RT, Roberts, SP, Moore, LJ, and Stokes, KA. Physical demands of refereeing rugby sevens matches at different competitive levels. J Strength Cond Res 35(11): 3164-3169, 2021-The aim of this study was to compare the physical demands of officiating across different competitive levels in rugby sevens. An observational design was used involving 27 referees (26 men and 1 woman, age: 27 ± 6 years, body mass [mean ± SD]: 78.5 ± 9.3 kg, and height: 179 ± 5 cm). Global Navigation Satellite Systems data were collected across a total of 114 matches during 5 separate rugby sevens tournaments played in England-between May and July 2018-categorized into 4 competitive levels: (a) international, (b) professional, (c) semiprofessional, and (d) amateur. Compared with referees officiating at the international, professional, and semiprofessional levels, referees officiating at the amateur level covered less total (p < 0.001) and relative distance (p < 0.001). In addition, these referees covered more distance walking and jogging (p < 0.001). Amateur referees also completed fewer sprints (p = 0.006), repeated high-intensity efforts (RHIEs) per game (p < 0.001), and spent longer between RHIEs (p = 0.015). Finally, for the amateur referees, the duration of the longest repeated high-intensity bout (i.e., worst case scenario) was lower (p < 0.001), with less distance covered (p < 0.001) and fewer high-intensity accelerations (p < 0.001). Refereeing rugby sevens is therefore more physically demanding at higher competitive levels, particularly in terms of high-intensity efforts. The results provide vital information for practitioners involved in the physical preparation of rugby sevens referees.


Asunto(s)
Rugby , Carrera , Adulto , Femenino , Sistemas de Información Geográfica , Humanos , Masculino , Caminata , Adulto Joven
6.
J Sports Sci ; 37(15): 1778-1786, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30909849

RESUMEN

Compared to sports performers, relatively little is known about how sports officials make decisions at a perceptual-cognitive level. Thus, this study examined the decision-making accuracy and gaze behaviour of rugby union referees of varying skill levels while reviewing scrum scenarios. Elite (n = 9) and trainee (n = 9) referees, as well as experienced players (n = 9), made decisions while watching ten projected scrum clips and wearing a mobile eye-tracker. Decision-making accuracy and gaze behaviour were recorded for each scrum. The elite and trainee referees made more accurate decisions than the players, and differences in gaze behavior were observed. The elite and trainee referees displayed lower search rates, spent more time fixating central-pack (i.e., front rows, binds, and contact point) and less time fixating outer-pack (e.g., second rows) and non-pack (e.g., other) locations, and exhibited lower entropy than the players. While search rate failed to predict decision-making accuracy, the time spent fixating central-, outer-, and non-pack locations, as well as entropy, were significant predictors. The findings have implications for training perceptual-cognitive skill among sports officials.


Asunto(s)
Cognición , Toma de Decisiones , Fijación Ocular , Fútbol Americano/psicología , Percepción Visual , Adulto , Atención , Medidas del Movimiento Ocular , Humanos , Competencia Profesional , Análisis de Regresión , Grabación en Video , Adulto Joven
7.
Scand J Med Sci Sports ; 28(1): 340-347, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28581687

RESUMEN

Research suggests that experiencing a moderate number of adverse life events can benefit future stress responses. This study explored the relationship between adverse life (ie, non-sport) events and cardiovascular responses to, and performance during, a pressurized sporting task. One hundred participants (64 men, 36 women; Mage =21.94 years, SDage =4.98) reported the number of adverse life events (eg, serious accident or injury) they had encountered before completing a pressurized dart-throwing task during which performance was recorded. Before the task, participants' demand and resource evaluations and cardiovascular reactivity were assessed. Adverse life events did not impact demand and resource evaluations. However, participants who reported 4-7 adverse life events displayed cardiovascular responses more reflective of a challenge state (relatively lower total peripheral resistance and/or higher cardiac output) compared to those who reported a lower (<4) or higher (>7) number of events. Furthermore, participants who reported 3-13 adverse life events outperformed those who reported a lower (<3) or higher (>13) number of events. Supplementary analyses suggested that this relationship might be due to a small number of extreme values. However, after outlier analyses, a significant linear relationship remained suggesting that a higher number of adverse life events facilitated performance. The results suggest that experiencing a moderate to high number of adverse life events might have beneficial effects on subsequent cardiovascular responses and performance under pressure. Practitioners should therefore consider prior brushes with adversity when identifying athletes who are likely to excel during stressful competition.


Asunto(s)
Rendimiento Atlético/psicología , Sistema Cardiovascular , Estrés Psicológico , Adulto , Atletas , Femenino , Humanos , Masculino , Resistencia Vascular , Adulto Joven
8.
Surg Endosc ; 29(9): 2553-60, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25427414

RESUMEN

BACKGROUND: Research has demonstrated the benefits of robotic surgery for the patient; however, research examining the benefits of robotic technology for the surgeon is limited. This study aimed to adopt validated measures of workload, mental effort, and gaze control to assess the benefits of robotic surgery for the surgeon. We predicted that the performance of surgical training tasks on a surgical robot would require lower investments of workload and mental effort, and would be accompanied by superior gaze control and better performance, when compared to conventional laparoscopy. METHODS: Thirty-two surgeons performed two trials on a ball pick-and-drop task and a rope-threading task on both robotic and laparoscopic systems. Measures of workload (the surgery task load index), mental effort (subjective: rating scale for mental effort and objective: standard deviation of beat-to-beat intervals), gaze control (using a mobile eye movement recorder), and task performance (completion time and number of errors) were recorded. RESULTS: As expected, surgeons performed both tasks more quickly and accurately (with fewer errors) on the robotic system. Self-reported measures of workload and mental effort were significantly lower on the robotic system compared to the laparoscopic system. Similarly, an objective cardiovascular measure of mental effort revealed lower investment of mental effort when using the robotic platform relative to the laparoscopic platform. Gaze control distinguished the robotic from the laparoscopic systems, but not in the predicted fashion, with the robotic system associated with poorer (more novice like) gaze control. CONCLUSIONS: The findings highlight the benefits of robotic technology for surgical operators. Specifically, they suggest that tasks can be performed more proficiently, at a lower workload, and with the investment of less mental effort, this may allow surgeons greater cognitive resources for dealing with other demands such as communication, decision-making, or periods of increased complexity in the operating room.


Asunto(s)
Laparoscopía , Procedimientos Quirúrgicos Robotizados , Cirujanos , Análisis y Desempeño de Tareas , Carga de Trabajo , Adulto , Femenino , Humanos , Masculino
9.
J Sport Exerc Psychol ; 37(3): 339-43, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26265345

RESUMEN

Competitive situations often hinge on one pressurized moment. In these situations, individuals' psychophysiological states determine performance, with a challenge state associated with better performance than a threat state. But what can be done if an individual experiences a threat state? This study examined one potential solution: arousal reappraisal. Fifty participants received either arousal reappraisal or control instructions before performing a pressurized, single-trial, motor task. Although both groups initially displayed cardiovascular responses consistent with a threat state, the reappraisal group displayed a cardiovascular response more reflective of a challenge state (relatively higher cardiac output and/or lower total peripheral resistance) after the reappraisal manipulation. Furthermore, despite performing similarly at baseline, the reappraisal group outperformed the control group during the pressurized task. The results demonstrate that encouraging individuals to interpret heightened physiological arousal as a tool that can help maximize performance can result in more adaptive cardiovascular responses and motor performance under pressure.


Asunto(s)
Nivel de Alerta/fisiología , Golf/psicología , Estrés Psicológico/psicología , Adolescente , Adulto , Gasto Cardíaco/fisiología , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Resistencia Vascular/fisiología , Adulto Joven
10.
Stress Health ; 40(3): e3358, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38108652

RESUMEN

It has been argued that habitually appraising stressful events as more of a threat (i.e., situational demands exceed personal coping resources) may increase one's risk of ill-health (e.g., depression). However, while first theorized 15 years ago, little research has tested this assertion. Thus, this study offered a novel test of the associations between trait challenge and threat appraisals and health-related outcomes (i.e., mental health symptomology, psychological well-being, and physical health complaints). Three hundred and ninety-five participants (251 female, 144 male; Mage = 22.50 years, SD = 5.33) completed valid and reliable measures of trait challenge and threat appraisals, mental health (i.e., symptoms of depression and anxiety), well-being (e.g., subjective vitality), and physical health complaints (e.g., respiratory illnesses). Regression analyses revealed that trait challenge and threat appraisals accounted for a significant proportion of variance in all outcomes after controlling for age and gender, with a tendency to appraise stressful events as more of a threat associated with poorer mental health (i.e., greater depression symptomology), well-being (e.g., lower vitality), and physical health (e.g., more respiratory illnesses). Taken together, the findings highlight the importance of trait challenge and threat appraisals for health, although further research is needed using stronger designs (e.g., longitudinal) to enable a more causal understanding.


Asunto(s)
Ansiedad , Depresión , Estrés Psicológico , Humanos , Femenino , Masculino , Adulto , Estrés Psicológico/psicología , Adulto Joven , Depresión/psicología , Ansiedad/psicología , Estado de Salud , Adaptación Psicológica , Salud Mental , Adolescente , Persona de Mediana Edad
11.
Anxiety Stress Coping ; 37(2): 233-250, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-37665577

RESUMEN

BACKGROUND AND OBJECTIVES: Recent research has shown that lifetime stressor exposure can negatively impact sport performers. However, this work has predominantly relied on quantitative methods, which has provided limited information regarding how stressors occurring over the life course affect health, well-being, and performance. This study aimed to explore how relatively high levels of lifetime (non-sport and sport-specific) stressor exposure influenced sport performers' health, well-being, and performance. METHODS AND DESIGN: To identify participants who had experienced high lifetime (non-sport and sport-specific) stressors, we used criterion-based purposeful sampling from a prior study. Subsequently, semi-structured interviews, complemented by timelining, were conducted with 22 sport performers (17 female; Mage = 25.89, SD = 10.20). RESULTS: We used reflexive thematic analysis to develop three overarching themes that illustrate how high lifetime (non-sport and sport-specific) stressor exposure influences sport performers' health, well-being, and performance. These were: psychological (e.g., maladaptive coping strategies), social (e.g., difficulties in building relationships), and behavioral (e.g., risky behaviors) factors. CONCLUSIONS: These findings can help practitioners identify sport performers at risk of developing stress-related health, well-being, and performance problems, and may aid the development of effective interventions.


Asunto(s)
Deportes , Estrés Psicológico , Humanos , Femenino , Adulto , Deportes/psicología , Asunción de Riesgos , Habilidades de Afrontamiento , Acontecimientos que Cambian la Vida
12.
Women Birth ; 37(5): 101639, 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38968701

RESUMEN

PROBLEM: UK midwives report high work-related stress, which can negatively impact their health and wellbeing, with many considering leaving the profession. BACKGROUND: An occupational stress audit guides the implementation of stress management intervention, by identifying which stressors have the most negative impact and why, and highlighting "at risk" groups. AIM: To conduct a concurrent mixed-methods stress audit with UK midwives in an NHS Trust. METHODS: Seventy-one midwives (Mage= 39 years, SD = 11) completed a survey assessing stressors (e.g., relationships), stress appraisals (i.e., challenge vs. threat), coping strategies (e.g., avoidance-focused), and outcomes (i.e., mental health, performance, and intention to leave). Ten midwives (Mage = 42 years, SD = 10) participated in semi-structured interviews. FINDINGS: Quantitative data revealed that more work-related demands, poorer peer support and relationships, and threat appraisals predicted worse mental health. Moreover, less control and more work-related demands predicted poorer performance, while less control, poorer manager support, more change-related demands, and threat appraisals predicted greater intention to leave. Qualitative data generated three themes: organisational pressures exacerbated by unexpected changes; individualised responses but largely debilitative emotions; and personal coping and power of social support. DISCUSSION AND CONCLUSION: This study offered a comprehensive and novel insight into the stress experiences of UK midwives, highlighting targets for future stress management interventions, including key stressors (e.g., manager support), underlying mechanisms (e.g., stress appraisals), and "at-risk" groups (e.g., night shift workers). Practical recommendations are provided for stakeholders operating at multiple levels (e.g., midwife, trust, policy) to better support midwives with work-related stress.

13.
Women Birth ; : 101589, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38580584

RESUMEN

BACKGROUND: Work-related stress is high in midwifery with negative implications for midwives' health and performance. This systematic review therefore examined which stress management interventions (SMIs) are most effective at reducing occupational stress and improving midwives' health and well-being, performance, and job satisfaction. METHODS: A systematic review included studies if they were: investigating midwives or student midwives; examining an individual- or organisation-level intervention; reporting the intervention effects on at least one outcome (e.g., job performance); peer-reviewed; and published in English. Methodological quality was assessed using the Mixed Methods Appraisal Tool. A narrative synthesis was conducted and data were presented by SMI level (i.e., individual vs. organisation) and modality type (e.g., mindfulness, care model). Sum codes were used to compare the effects of individual- and organisation-level SMIs on outcomes. FINDINGS: From 2605 studies identified, 30 were eligible (18 individual- and 12 organisation-level SMIs). Eight studies were deemed low quality. While individual- and organisation-level SMIs were equally effective in improving job satisfaction and performance, there was a trend for organisation-level SMIs more effectively reducing work stress and improving health and well-being. Specific individual- (i.e., mindfulness, simulation training) and organisation-level (i.e., reflective groups, midwifery care models) SMIs were most beneficial. CONCLUSION: It is recommended that health practitioners and policy makers implement interventions that target both individual- and organisation-levels to optimally support midwives' work stress, health, well-being, and performance. Notwithstanding these findings and implications, some studies had poor methodological quality; thus, future research should better follow intervention reporting guidelines.

14.
Int J Sport Exerc Psychol ; 22(3): 553-571, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38859903

RESUMEN

Although greater lifetime stressor exposure has been associated with physical and mental health issues in the general population, relatively little is known about how lifetime stressors impact the physical and mental health of elite athletes or the factors moderating this association. Given that many elite athletes show signs of perfectionism, and that this trait has been linked with ill-health, it is possible that perfectionism may moderate the lifetime stressor-health relationship. To test this possibility, we examined how cumulative lifetime stressor exposure was associated with general mental and physical health complaints in elite athletes, and the extent to which these associations were moderated by perfectionism. Participants were 110 elite athletes (64 female; M age = 29.98 years, SD = 10.54) who completed assessments of lifetime stressor exposure, physical health, psychological distress, and perfectionism. As hypothesised, hierarchical regression analyses revealed that experiencing more severe lifetime stressors was related to poorer physical and mental health. Furthermore, self-oriented perfectionism moderated the association between lifetime stressor count and severity and physical health, but not mental health. Overall, these data demonstrate stressor-specific effects among elite athletes and highlight the potential importance of assessing lifetime stressor exposure and perfectionistic tendencies in order to improve athlete health and well-being.

15.
Phys Chem Chem Phys ; 15(32): 13489-98, 2013 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-23824264

RESUMEN

This paper presents a study of the optical trapping of aerosols containing ionic liquid (IL). Droplets comprised of aqueous solutions of the IL ethylammonium nitrate (EAN) are demonstrated to be readily trapped by optical tweezers and are characterized spectroscopically, by analysing the morphology dependent resonances present within backscattered light originating from a broadband light emitting diode. The response of the droplets to conditions of varying relative humidity has also been investigated, as an important first step in measuring the uptake of gases by ILs. Finally, a comparison between broadband Mie scattering and cavity enhanced Raman spectroscopies is provided.


Asunto(s)
Líquidos Iónicos/química , Pinzas Ópticas , Compuestos de Amonio Cuaternario/química , Soluciones
16.
J Sport Exerc Psychol ; 35(6): 551-62, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24334317

RESUMEN

The present research examined the immediate impact of challenge and threat states on golf performance in both real competition and a laboratory-based task. In Study 1, 199 experienced golfers reported their evaluations of competition demands and personal coping resources before a golf competition. Evaluating the competition as a challenge (i.e., sufficient resources to cope with demands) was associated with superior performance. In Study 2, 60 experienced golfers randomly received challenge or threat manipulation instructions and then performed a competitive golf-putting task. Challenge and threat states were successfully manipulated and the challenge group outperformed the threat group. Furthermore, the challenge group reported less anxiety, more facilitative interpretations of anxiety, less conscious processing, and displayed longer quiet eye durations. However, these variables failed to mediate the group-performance relationship. These studies demonstrate the importance of considering preperformance psychophysiological states when examining the influence of competitive pressure on motor performance.


Asunto(s)
Conducta Competitiva , Golf/psicología , Estrés Psicológico , Adulto , Rendimiento Atlético/psicología , Inglaterra , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
17.
Nano Lett ; 10(10): 4266-72, 2010 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-20853830

RESUMEN

A spatially modulated laser is used to produce multiple localized thermal gradients in a colloidal sample placed above a gold surface. We use an optical microscope to observe real time dynamics of the resulting two-dimensional colloidal crystal grains and find that grain rotation-induced grain coalescence (GRIGC) occurs with the rotation of both grains before coalescence. Control over the grain size shows that the time scale for grain boundary annealing in our system is in good agreement with theoretical expressions formulated for nanocrystal growth.

18.
J Sports Med Phys Fitness ; 61(6): 788-796, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33146494

RESUMEN

BACKGROUND: The purpose of this study was to compare the match demands of officiating 15-a-side rugby union at different competitive levels. METHODS: Data was collected using Global Navigation Satellite Systems from 21 referees during 82 competitive rugby union matches across three different competitive levels: 1) professional; 2) semi-professional; 3) amateur. RESULTS: Compared with referees at the professional and semi-professional levels, referees at the amateur level covered less total distance (P=0.005). Additionally, these referees covered less distance jogging, and at low and medium intensity (all P<0.05), and had less time between repeated high-intensity efforts (P<0.001). Furthermore, compared with referees at the semi-professional and amateur levels, referees at the professional level had a higher sprint duration and covered more distance sprinting (all P<0.05), and achieved a higher maximal speed during the longest repeated high-intensity effort or "worst-case scenario" (P=0.026). The professional level referees also displayed a lower average heart rate (P<0.001), spent a higher percentage of time at <60% HRmax (P<0.001), and a lower percentage of time between 71% and 80% HRmax (P=0.004). Finally, external and internal load were strongly correlated for referees at the semi-professional level only (r=0.75, P<0.001). CONCLUSIONS: Overall, the findings demonstrate that refereeing 15-a-side rugby union is more physically demanding at higher competitive levels, particularly in terms of high-intensity efforts. The results provide important information for practitioners involved in the physical preparation and training of rugby union referees.


Asunto(s)
Fútbol Americano/clasificación , Carrera/fisiología , Adulto , Entrenamiento Aeróbico/educación , Fútbol Americano/fisiología , Frecuencia Cardíaca , Humanos , Masculino
19.
Tumour Biol ; 31(5): 495-502, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20563897

RESUMEN

A highly conserved region of 21 amino acids flanked by cysteine residues, contained within a larger repeated domain, has been proposed to be the antibody-binding site in the ovarian cancer biomarker CA125 (MUC16). In this study solid-phase peptide synthesis with Fmoc protection chemistry was used to assemble a 21-mer peptide corresponding to the most frequently occurring antibody binding sequence in CA125. Potentially significant sequence variants were also synthesized. Peptide secondary structure was investigated using Fourier transform infrared spectroscopy, revealing the consensus sequence peptide to be largely unstructured at physiological pH whether the cysteine residues were reduced or were oxidized to form an intramolecular disulfide bond. Substitution of serine for proline at position 8 (P8S) results in ß-sheet formation in peptides involved in intramolecular disulfide bonds. This ß-sheet structure does not persist in peptides incapable of intramolecular disulfide bonding because of sequence nor in peptides treated with the reducing agent dithiothreitol. In CA125, P8S is predicted to occur in ∼25% of repeat domains, suggesting that this structural motif is a non-negligible contributor to overall structure and function. These findings suggest that future structural characterization efforts of CA125 should be especially mindful of the amino acid sequence and oxidation state of the protein.


Asunto(s)
Biomarcadores de Tumor/química , Biomarcadores de Tumor/síntesis química , Antígeno Ca-125/química , Epítopos de Linfocito B/química , Proteínas de la Membrana/química , Secuencia de Aminoácidos , Femenino , Humanos , Neoplasias Ováricas/metabolismo , Estructura Secundaria de Proteína , Espectroscopía Infrarroja por Transformada de Fourier
20.
Anxiety Stress Coping ; 33(5): 497-510, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32421380

RESUMEN

Background and Objectives: Individuals evaluate the demands and resources associated with a pressurized situation, which leads to distinct patterns of cardiovascular responses. While it is accepted that cognitive evaluations are updated throughout a pressurized situation, to date, cardiovascular markers have only been recorded immediately before, or averaged across, these situations. Thus, this study examined the influence of in-task performance-related feedback on cardiovascular markers of challenge and threat to explore fluctuations in these markers. Methods and Design: Forty participants completed a pressurized visual search task while cardiovascular markers of challenge and threat were recorded. During the task, participants received either positive or negative feedback via distinct auditory tones to induce a challenge or threat state. Following task completion, cardiovascular markers were recorded during a recovery phase. Results: Participants' cardiovascular responses changed across the experimental protocol. Specifically, while participants displayed a cardiovascular response more reflective of a challenge state following in-task performance-related feedback, participants exhibited a response more akin to a threat state later during the recovery phase. Conclusions: In-task auditory performance-related feedback promoted cardiovascular markers of a challenge state. These markers fluctuated over the experiment, suggesting that they, and presumably underlying demand and resource evaluations, are relatively dynamic in nature.


Asunto(s)
Estimulación Acústica/métodos , Presión Sanguínea/fisiología , Frecuencia Cardíaca/fisiología , Desempeño Psicomotor/fisiología , Estrés Psicológico/fisiopatología , Adulto , Retroalimentación , Femenino , Humanos , Masculino , Adulto Joven
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